Finite element analysis of a zoned earth dam under earthquake excitation

Abstract

This paper presents a finite element analysis of a zoned earth dam under the effects of earthquake conditions. GeoStudio software, and in particular the sub-programs SEEP/W and QUAKE/W were used, and the earthquake used in the analysis was an Iraqi earthquake that occurred in Ali Al-Garbi, within the Missan governorate. The Haditha dam section data was used for the hypothetical dam construction. The total length of length of this dam is 9,064 metres, which includes 8,875 metres of earth fill, and the maximum height of the dam is 57 m. The shell is constructed from a mix of sand and gravel, with an average particle diameter ranging from 0.24 to 16.7 mm. Three different properties were used to represent the core material, and each of these properties was analysed under three different heads of water on the upstream side. The results showed that high water levels at the upstream side of the dam heavily influenced the analysis results. The water flux, water conductivity, and peak displacement all increased with the increase in the water level upstream of the dam. For a water level equal to 152 m, the maximum values of water flux, water conductivity, and maximum displacement were 3.951 × 10-3 m2/sec, 6.654 × 10-3, and 2.03 m, respectively, while where the water level was 143 m, these values were equal to 2.023 × 10-3 m2/sec, 3.995 × 10-3, and 1.85 m, respectively. Further analysis showed that the water flux, water conductivity, and peak displacement increased with increases in the void ratio and degree of saturation of the clay core material, moving from 2.023 × 10-3 to 3.951 × 10-3 m2/sec for water flux, from 3.995 × 10-3 to 6.654 × 10-3 for water conductivity, and from 1.85 to 2.03 m for peak displacement.